[clamper1797]

I would believe 700 feet high and 300 miles inland

[RightWhale]

To reach 300 miles inland it would have to be much more than 700 feet high as it contacts the shore. A very rough estimate: Maybe 10 to 20 miles high, clearly impossible since there isn't enough deep water in the ocean. The 700 foot crest might reach 3 miles inland, probably less in most places.